Issue with -C and -N parameters in Nexmon CSI tool

[asjkb1231]

Hello,

I am currently using the Nexmon CSI tool to extract Channel State Information (CSI) in a setup involving two Asus RT-AC86U devices and a PC. One Asus RT-AC86U is installed with the Nexmon CSI tool in monitor mode, the other Asus RT-AC86U acts as a receiver, and the PC is used as a transmitter.

The Asus RT-AC86U has four antennas and the PC has two, so I am expecting to get CSI from 8 subcarriers. However, I am not able to get CSI from all 8 subcarriers. I am focusing on the -C and -N parameters used in the command /jffs/mcp -c 36/80 -C 1 -N 1 as I believe controlling these values might solve my problem.

I have tried different combinations of -C and -N parameters, and I am attaching Wireshark screenshots for two of these combinations: -C 2 -N 4 and -C 0x0f -N 0x0f. Each combination results in different paths and numbers of paths, but I am still not able to get CSI from all 8 subcarriers.

For example, with -C 2 -N 4, I get CSI from one path 0011. However, when I use -C 0x0f -N 0x0f, I get 16 paths, which are 0000,0008,0010,0018,0001,0009,0011,0019,0002,000a,0012,001a,0003,000b,0013,001b in order. But the values for paths 0010,0018,0011,0019,0012,001a,0013,001b are all 0, which is not what I expected.

I would appreciate any guidance on how to use the -C and -N parameters to get CSI from all 8 subcarriers. Thank you in advance for your help.

Best regards,

-C 4 -N 2

-C 0x0f -N 0x0f